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Filename Size Restrictions
The file reference can be either in MPE/iX or POSIX namespace.
The MPE file domain consists of MPE accounts, MPE groups and files which
reside in these groups.accounts. The MPE file domain is a 3 level
Hierarchical File System (HFS).
The POSIX file domain is considered a superset of the MPE file domain.
The POSIX file domain consists of a root (/) and POSIX directories, which
can contain additional directories or files. The POSIX file domain is a
multi-level Hierarchical File System.
POSIX is implemented on MPE/iX in such a manor that it is a superset of
MPE. MPE accounts are now under the POSIX root (/) and are treated as
special directories, likewise MPE groups are located under accounts and
again are treated as special directories.
As a result of this implementation, files in the MPE file domain can be
accessed by MPE applications, and since the POSIX file domain is a
superset of the MPE file domain, POSIX applications can also access these
files. In general MPE applications cannot access files in the POSIX file
domain unless the application, or the file procedures it calls, are
specifically coded to do so.
MPE/iX Namespace
If the file reference does not begin with a dot or a slash, it is parsed
according to the MPE/iX syntax and has the following format:
filename [/lockword] [.groupname [.acctname]]
MPE/iX names must contain from one to eight alphanumeric characters,
beginning with an alphabetic character. If acctname is specified, you
must change directory (CD) access to the target group in the account.
The default groupname and acctname are the logon group and account.
Filenames in MPE name space are not case sensitive, and are all shifted
to uppercase.
POSIX Namespace
If the file reference begins with a dot (.) or a slash (/), it is parsed
according to the POSIX syntax. In this case the file reference can be
./Directory 1/Directory 2/ Directory 3/....
The following syntax rules apply:
* File names are not shifted to uppercase.
* File names can be up to 254 characters in length for absolute
pathnames, and 253 characters for relative pathnames.
* File names can begin with, and contain, any of the following
characters:
Table A-1.
------------------------------------------------------------------------
| | | | | | |
| | a-z | A-Z, | 0-9, | _, | . |
| | | | | | |
------------------------------------------------------------------------
* File names can contain (but not begin with) a dash (-).
* File names are of the form (path/filename)
where the path/filename combination can have a maximum of 255
characters.
For more information, refer to the New Features of MPE/iX: Using The
Hierarchical File System Reference Manual (32650-90351) for accepted
syntax of file names and directories.
Table A-2.
--------------------------------------------------------------------
| | | |
| Sample File Name | MPE File Name Space | POSIX File Name |
| | | Space |
| | | |
--------------------------------------------------------------------
| | | |
| FILENAME | FILENAME | FILENAME |
| | | |
--------------------------------------------------------------------
| | | |
| filename | FILENAME | filename |
| | | |
--------------------------------------------------------------------
| | | |
| longfilename | Invalid MPE file | longfilename |
| | name | |
| | | |
--------------------------------------------------------------------
| | | |
| Read_Me | Invalid MPE file | Read_Me |
| | name | |
| | | |
--------------------------------------------------------------------
NOTE The file identifiers "./FILENAME" and "./filename" refer to two
different files in the POSIX name space since character case is
accepted in the POSIX name space.
Example 1:
Files in the MPE file domain in PUB.SYS (MPE syntax) are also viewed as
being a part of the POSIX file domain in /SYS/PUB/ (POSIX syntax).
Table A-3.
-------------------------------------------
| |
| :listf log@.pub.sys |
| |
-------------------------------------------
| | | |
| FILENAME | | |
| | | |
-------------------------------------------
| | | |
| LOG | LOG0112 | LOG0113 |
| | | |
-------------------------------------------
| | | |
| | or | |
| | | |
-------------------------------------------
| |
| :listfile /SYS/PUB/LOG@ |
| |
-------------------------------------------
| |
| PATH= /SYS/PUB/ |
| |
-------------------------------------------
| | | |
| LOG | LOG0112 | LOG0113 |
| | | |
-------------------------------------------
Example 2:
Files in the POSIX file domain in "/SYS/PUB/directory1/directory2/"
(POSIX syntax) are outside of the MPE file domain.
:listf /SYS/PUB/directory1/directory2/
File name missing. (CIERR 531)
:listfile /SYS/PUB/directory1/directory2
PATH= /SYS/PUB/directory1/
directory2/
PATH = /SYS/PUB/directory1/directory2/
TESTDATA
NOTE The MPE listf command executes against files in the MPE file
domain. The MPE command listfile created for POSIX executes
against files in both the MPE and POSIX file domains.